Generally, multicast service transmits corresponding data by adjusting modulation and coding rate to the user having the lowest channel gain among the users in order to allow all users in a corresponding multicast user group to normally receive the multicast service.
For example, in Multimedia Broadcast Multicast Service (MBMS) system defined by 3rd Generation Partnership Project (3GPP), BroadCast MultiCast Service (BCMCS) system defined by 3rd Generation Partnership Project-2 (3GPP2), and 802.16 system defined by IEEE for multicast services, a base station transmits corresponding data by adjusting the modulation and coding rate to the user having the lowest channel gain without using Channel Quality Information (CQI). The foregoing conventional data transmission method can reduce the system complexity and obtain macro diversity gain. However, the conventional data transmission method may cause a waste of transmission power and cannot efficiently use wireless resources.